1. Field of the Invention
The present invention relates to a food degassing bag for storing food such as coffee beans and miso, and relates to a food degassing bag capable of degassing carbon dioxide gas produced from food in a packaged state.
2. Description of the Related Art
For example, when coffee beans are bagged, carbon dioxide gas produced from the coffee beans may fill the bag to rupture the bag. Therefore, conventionally, a special valve has been attached to the bag to perform appropriate gas ventilation so as to adjust the internal pressure of the bag.
Such a bag attached with a special valve is bulky in valve configuration, which causes an inconvenience that unevenness is formed on the bag surface. Moreover, because the valve as a separate member is attached to the bag, the manufacturing cost becomes extremely high.
On the other hand, Patent Document 1 describes a packaging bag having a gas venting operation. For this packaging bag, a non-breathable outer film having oxygen barrier properties and a breathable inner film that transmits oxygen are overlaid on top of each other, and a gas venting pore portion is provided in the outer film.
However, the packaging bag described in Document 1, for which the inner film with breathability is overlaid on the outer film having oxygen barrier properties, has thus required many steps for manufacturing the films having a gas venting operation.
The present applicant has therefore proposed earlier, as described in Patent Document 2, a food degassing bag for which a gas venting pore portion is formed to penetrate through one of the packaging films in a part where inner films of packaging films to form a bag body are joined to each other.
With this food degassing bag, because no pore portion is formed in a main body part of the bag body, it has succeeded in providing a food degassing bag with improved appearance. Also, because the pore portion is formed in the part where inner films are joined to each other, the possibility that the pore portion is deformed is also eliminated.
[Patent Document 1] Japanese Published Unexamined Patent Application No. H10-167335
[Patent Document 2] Japanese Utility Model Registration No. 3184474